GENETIC-VARIABILITY IN GROWTH-RATES OF MARINE DINOFLAGELLATES

The growth rates of thirty clones of Prorocentrum micans, twenty-two clones of Gonyaulax excavata and fifteen clones of Scrippsiella trochoidea, isolated from eight different water samples were measured under two environmental conditions. There was significant genetic variability in growth rates between clones. The amount of genetic variability between clones ranged from 10-27% (coefficient of variation) in Prorocentrum micans, 31-52% in Gonyaulax excavata and 11-20% in Scrippsiella trochoidea. Unlike Gonyaulax excavata and Scrippsiella trochoidea many different Prorocentrum micans clones had identical growth rates.